title: Ultrasound-guided adductor canal block for arthroscopic medial meniscectomy: a randomized, double-blind trial.
abstract: OBJECTIVE
  The saphenous nerve block using a landmark-based approach has shown promise in reducing postoperative pain in patients undergoing arthroscopic medial meniscectomy. We hypothesized that performing an ultrasound-guided adductor canal saphenous block as part of a multimodal analgesic regimen would result in improved analgesia after arthroscopic medial meniscectomy.
  
  
  METHODS
  Fifty patients presenting for ambulatory arthroscopic medial meniscectomy under general anesthesia were prospectively randomized to receive an ultrasound-guided adductor canal block with 0.5% ropivacaine or a sham subcutaneous injection of sterile saline. Our primary outcome was resting pain scores (numerical rating scale; NRS) upon arrival to the postanesthesia care unit (PACU). Secondary outcomes included NRS at six hours, 12 hr, 18 hr, and 24 hr; postoperative nausea; and postoperative opioid consumption.
  
  
  RESULTS
  There was a statistically significant difference in mean NRS pain scores upon arrival to the PACU (P = 0.03): block group NRS = 1.71 (95% confidence interval [CI] 0.73 to 2.68) vs sham group NRS = 3.25 (95% CI 2.27 to 4.23). Cumulative opioid consumption (represented in oral morphine equivalents) over 24 hr was 71.8 mg (95% CI 56.5 to 87.2) in the sham group vs 44.9 mg (95% CI 29.5 to 60.2) in the block group (P = 0.016).
  
  
  CONCLUSIONS
  An ultrasound-guided block at the adductor canal as part of a combined multimodal analgesic regimen significantly reduces resting pain scores in the PACU following arthroscopic medial meniscectomy. Furthermore, 24-hr postoperative opioid consumption and pain scores were also reduced.
authors.affiliation: Department of Anesthesiology, Virginia Mason Medical Center, 1100 Ninth Ave, Mailstop: B2-AN, Seattle, WA 98101, USA.
authors.forename: Neil A
authors.initials: NA
authors.lastname: Hanson
authors.forename: Ryan E
authors.initials: RE
authors.lastname: Derby
authors.forename: David B
authors.initials: DB
authors.lastname: Auyong
authors.forename: Francis V
authors.initials: FV
authors.lastname: Salinas
authors.forename: Christina
authors.initials: C
authors.lastname: Delucca
authors.forename: Ryan
authors.initials: R
authors.lastname: Nagy
authors.forename: Zhuoxin
authors.initials: Z
authors.lastname: Yu
authors.forename: April E
authors.initials: AE
authors.lastname: Slee
mesh_terms: D000328:Adult; D000368:Aged; D000556:Ambulatory Surgical Procedures / Q000379:methods; D000701:Analgesics, Opioid / Q000008:administration & dosage; D001182:Arthroscopy / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008592:Menisci, Tibial / Q000601:surgery*; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000453:epidemiology / Q000517:prevention & control*; D020250:Postoperative Nausea and Vomiting / Q000453:epidemiology; D011446:Prospective Studies; D013997:Time Factors; D018084:Ultrasonography, Interventional / Q000379:methods
chemical_list: D000701:Analgesics, Opioid